Especiação de cromo em cimentos e derivados de cimento brasileiros Chromium speciation in cement and cement-related materials from Brazil

• Main Authors: Wladiana Oliveira Matos, Joaquim Araújo Nóbrega
• Format: Article
• Language: English
• Published: Sociedade Brasileira de Química 2009-01-01
• Series: Química Nova
• Subjects: chromium; speciation; cement
• Online Access: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-40422009000800020

<abstract language="eng">A method for determination of Cr(III) and Cr(VI) in cement and cement-related materials was studied. Molecular absorption spectrophotometry based on 1,5-diphenylcarbazide as chromogenic reagent was used for determination of Cr(VI) after alkaline extraction. The total chromium concentration was determined using flame atomic absorption spectrometry (FAAS) after complete sample decomposition by fusion. The quantification of Cr(III) was accomplished by subtracting the Cr(VI) concentration from the total chromium concentration. The concentration of Cr(III) in the samples ranged from 10.9 to 88.0 mg kg-1, whereas only in few samples the Cr(VI) concentration was higher than the value established by the European Community to this type of sample [2 mg kg-1 Cr(VI)].